N‐(2‐Thiophenesulfonyl)prolinamide could be easily introduced into Montmorillonite by a simple ion‐exchange reaction. The asymmetric aldolreactions between various isatins with acetone or acetaldehyde using a heterogeneous Montmorillonite‐entrapped organocatalyst afforded products with high enantioselectivity. The catalyst was readily reusable without significant loss of catalytic activity or enantioselectivity.